1. Field of the Invention
The present invention relates to a radiation image capturing system, a radiation image capturing method, and a program for controlling a plurality of image capturing apparatus of different specifications under given image capturing conditions to capture radiation images.
2. Description of the Related Art
In the medical field, there have widely been used radiation image capturing apparatus which apply a radiation to a subject and guide the radiation that has passed through the subject to a radiation detector, which captures a radiation image from the radiation.
One known radiation detector is a stimulable phosphor panel which stores a radiation energy representative of a radiation image in a phosphor. When the stimulable phosphor panel is irradiated with stimulating light, the phosphor emits stimulated light representative of the stored radiation image. The stimulable phosphor panel with the radiation image recorded therein is supplied to a reading apparatus which reads the stored radiation image as a visible radiation image.
In sites of medical practice such as operating rooms or the like, it is necessary to read recorded radiation image information immediately from a radiation detector for the purpose of quickly and appropriately treating the patient. As a radiation detector which meets such a requirement, there has been developed a radiation detector having a solid-state detector for converting a radiation directly into an electric signal or converting a radiation into visible light with a scintillator and then converting the visible light into an electric signal to read a detected radiation image.
There are available in the art various image capturing apparatus of different specifications for capturing radiation images using radiation detectors depending on the conditions of patients as subjects to be imaged and image capturing conditions including body regions to be imaged. Those different image capturing apparatus are controlled by respective processors of specifications corresponding to the specifications of the image capturing apparatus. According to a known radiographic system, various image capturing apparatus and processors are connected to a radiology information system (RIS) by an in-house network, and patient information and image capturing conditions set by the RIS which include image capturing methods, body regions to be imaged, radiation dose, etc. are supplied to the processors, which then control the corresponding image capturing apparatus to capture radiation images (see Japanese Laid-Open Patent Publication No. 2006-247137).
There has been also proposed in the art an apparatus for applying a radiation at a constant dose to a detector, correcting the sensitivity of the detector such that the detected level from the detector reaches a predetermined level, and then capturing a radiation image based on the corrected sensitivity of the detector for thereby obtaining desired radiation image information (see Japanese Laid-Open Patent Publication No. 2007-057946).
However, the image capturing conditions set in each of the image capturing apparatus vary depending on not only the body region to be imaged, but also the specifications of the image capturing apparatus depending on its type. The operator needs to be considerably skilled in order to set image capturing conditions for obtaining desired radiation images. Particularly, it is highly difficult for doctors to grasp detailed specifications of image capturing apparatus and set image capturing conditions based on the detailed specifications. Therefore, it has been customary in the art for the doctor in charge of a patient to set an image capturing method, a body region to be imaged, etc. and thereafter for a radiological technician, who knows much about how to handle the image capturing apparatus, to select an image capturing apparatus to be used and set detailed image capturing conditions including a tube voltage, a tube current, an irradiation time, etc. which correspond to the selected image capturing apparatus and the body region to be imaged.
The above procedure for setting image capturing conditions is considerably burdensome for the radiological technician. It is highly probable for the radiological technician to make a mistake in setting image capturing conditions.
According to the related art disclosed in Japanese Laid-Open Patent Publication No. 2007-057946, only the sensitivity of the detector is corrected, but image capturing conditions are not adjusted according to a body region to be imaged and an image capturing apparatus to be used. In this case, the dose of a radiation applied to the subject remains the same irrespectively of the body region to be imaged and the sensitivity of the detector. Even if a detector of high sensitivity is used, it does not contribute to a reduction in the dose of the applied radiation, an optimization of the dose of the radiation (i.e., an appropriate exposure) or a high image quality.